Generally, common household vacuum cleaners are equipped with many interchangeable accessories to be used for cleaning a variety of environments, such as carpets, curtains, corner, slit, etc. However, in a situation when a common household vacuum cleaner is used to clean certain areas that are lack of lighting, such as the area under a bed or sofa, users usually will find that it is difficult to proceed with the cleaning work in such dark environment since the accessories of the conventional household vacuum cleaner are not fitted with light sources designed for facilitating the cleaning work in poor lighting. Thus, in addition to operate the household vacuum cleaner by one hand, the user may have to hold a flash light in another hand just for projecting light to such dark spot so as to proceed with the cleaning work.
A vacuum cleaner is a device that uses an air pump to create a partial vacuum for inducing an airflow to suck up dust and dirt from its dust inlet while enabling the included airflow to flow through a filter before being discharged out of the vacuum cleaner. There are already many prior arts relating to the conversion of wind power into kinetic energy that are applied in vacuum cleaners, such as the vacuum cleaners disclosed in U.S. Pat. No. 6,101,667, U.S. Pat. No. 6,055,702, U.S. Pat. No. 6,023,814, U.S. Pat. No. 6,261,379, JP2006051171 and JP10057287. Generally, the power generated form an electric generator built inside the vacuum cleaner of the abovementioned disclosures is fed to the indicator lights and the dust sensors for supporting the same to operate. Moreover, the vacuum cleaners disclosed in the abovementioned disclosures can be divided into two categories. One of which are vacuum cleaners, disclosed in U.S. Pat. No. 6,261,379, JP2006051171 and JP1005728, which have impellers or electric generators being received inside their vacuum heads for enabling the induced airflow to be used directly for driving the impellers or the electric generators as soon as it is sucked into the vacuum cleaners from the vacuum heads. Nevertheless, although the applying of the airflow directly from the vacuum cleaner head upon the impeller or electric generator can be implemented directly and easily, the airflow directly from the vacuum cleaner head usually is saturated with dust and dirt, or even hairs and fibers that may easily cause the rotary elements in the impeller or electric generator to clog. As for the vacuum cleaners included in the other category, such as those disclosed in U.S. Pat. No. 6,101,667, U.S. Pat. No. 6,055,702, and U.S. Pat. No. 6,023,814, they generally designed with an additional inlet apart from the corresponding vacuum head to be used for housing the impellers or the electric generators therein, by which although the impellers or the electric generators can be prevented from being contaminated by the dust and dirt contained in the airflow from their vacuum heads, the impellers or the electric generators are still being exposed to the same airflow path inside the vacuum cleaners so that they can not be completely free from the contamination from the airflows of their vacuum heads. In addition, the wind power harvesters, such as the impellers and electric generators that are used in the aforementioned disclosures, are all being fixedly secured inside the vacuum cleaners, so that they can not be detached easily for maintenance.